Distribution of Precipitation and Climate Change: What Does It Mean?

The ambiguity of climate change really has no limits. The contradictory patterns of the Earth’s climate system cause this crisis to be unpredictable and likely impossible to solve. One component of climate change that is undisputed is the inevitability of a warming atmosphere – anthropogenic CO2 emissions have, and will drive global temperatures up a few degrees. While temperature is a rather straightforward aspect of the climate system, distribution of precipitation and atmospheric moisture are features that are a bit more irregular and inconsistent on a spatial scale. Atmospheric moisture is much more abundant today than it was in the 20th century due to warmer temperatures (higher temperatures can accommodate more water vapor in the atmosphere). Even though humidity has increased overall, some areas of the earth have been subjected to much drier conditions. That’s the core of the climate change water dilemma: some locations will become wetter while others will grow drier. So what does the distribution of precipitation and climate change mean for us?

Uneven Distribution of Precipitation

The Intergovernmental Panel on Climate Change (IPCC) has created multiple projections about global precipitation patterns over the next century. Almost all of the graphics they’ve produced reveal that subtropical latitudes will become drier, while equatorial and higher latitudes will experience increased moisture. IPCC models predict that rain intensity will increase throughout northern Europe, Canada, the northeastern U.S., tropical regions, and high latitudes such as the Arctic or Antarctica. On the other hand, the Mediterranean will experience drought, as well as the American southwest, northern Africa, Central America, Southern South America, and Australia. The increase or decrease of average annual rainfall will negatively impact agriculture; increased precipitation may damage crops while decreased rainfall will lower yields, possibly causing famine.

Human Migration due to Extreme Drought

Regions subject to extreme drought conditions will likely experience long-term human migration in the next few decades. People are more likely to move away from regions plagued by heat stress than from areas prone to other extreme weather events, such as floods. Human existence depends on water availability, thus arid regions will be particularly unpopular for future populations. Human migration is undoubtedly a repercussion of precipitation change because agricultural productivity declines in water-stressed locations where soil is dry and heat waves are frequent.

Zooming in on the U.S., the Midwest is projected to be the hardest hit by climate change according to the Nature Conservancy. The Great Plains statesare expected to undergo the greatest temperature increases. These dry forecasts may push people to move to wetter environments. Additionally, the Southwest will continue to see water scarcity issues due to decreased rainfall. These dry forecasts may push people to move to wetter environments.

U.S. Water Supply Risk. Image via the U.S. National Climate Assessment.

Climate Refuges and Refugees

The Pacific Northwest (PNW) has been in the spotlight for being a potential climate refuge. Water supply risk is moderate to low throughout Oregon and Washington, making these states attractive destinations for climate change refugees. Furthermore, the mild climate of the PNW will mitigate extreme temperatures and stabilize precipitation levels. Specifically, the Willamette Valley is said to be one of the best spots to live in a changing climate.

Outside of the U.S., subtropical inhabitants may seek higher latitudes to avoid the water scarcity of deserts, which are expanding due to the desertification of grassland ecosystems (examples include the growing Gobi Desert in China and the steppe ecoregions of Argentina). Productive land area is steadily decreasing each year in subtropical regions, which forces more and more people to move to urban locales thereby worsening the population density issues in large cities.

Extreme drought inhibits people from growing crops, thus their livelihoods are jeopardized, requiring them to seek asylum elsewhere. The issue of environmental refugees is underrepresented and should become a significant priority for international law in the upcoming century.

Water Innovation

In the midst of this gloomy discussion about deathly heat waves and widespread environmental migration, the water issue of climate change will force mankind into new territory: discovering new innovative techniques to conserve and harvest water. The infamous expression, “necessity is the mother of invention” could not be more relevant.

While the topic of climate change is depressing, the prospects for innovation don’t have to be. Environmental designers have been looking for new ways to extract water from extremely dry areas, such as the Atacama Desert in Chile or the Namib Desert in southern Africa. According to the Sierra Club, engineers are modeling systems based off of beetle adaptations to leech condensation from fog banks in deserts. Another example of an innovative water-harvesting device, designed by MIT, is a “fog catcher” – a large, coated stainless steel grid placed in deserts to produce water for agriculture. It’s virtually guaranteed that climate change will compel future generations to create more efficient methods to conserve valuable resources.

About The Author

Anne Weaveris a recent graduate of the University of Oregon where she earned a Bachelor of Science in environmental studies and a minor in business administration. Growing up discovering the natural beauty of the Pacific Northwest gave her a passion for both conservation and sustainability. She hopes to expand her knowledge of climate change by earning a Master’s degree in environmental science and specializing in biogeochemistry. As a foodie, her interests lie in cooking and baking, as well as traveling, camping, and exploring the outdoors.